Fuel feeding and carbureting system



Aug. 5, 1930.

J. C. COULOMBE FUEL FEEDING AND CARBURETING SYSTEM Filed March 5, 1925 INVENTOR :705'81011 C. Coulombe,

ATTORNEY Patented filing. 5, 1 ,77 1

UNITED, STATES PATENT OFFICE JOSEPH C. COULOMBE, OF KOKOMO, INDIANA FUEL FEEDING AND CARBUR-ETING SYSTEM Application filed March 5, 1925. Serial No. 13,226. 1

The invention herein described relates to duit 4. This metered opening may be dea fuel feeding and carbureting apparatus and signed to suit the conditions in any particuis particularly directed to an arrangement in 211' case, but'ordinarily a small opening about which the fuel reservoir is located at a lower the size of a #65 drill, with the standard 5' level than the carburetor, while the carburettype of gasolene fuel pipe is adequate. 55 or, through its connections, provides for rais- The condult 4, is connected to the carbureting the fuel and producing the properly ator body 7, through the usual connection as .tenuated mixture for an internal combustion at 8, and the fuel drawn through said conduit, engine. It is of simple and reliable and effirst enters an accelerating well 9, through a fieient construction and the system provides valve opening 10. T hisvalve opening 10, as 60 againstflooding. illustrated, is formed in an adjustable valve The above statement indicates, in general, seat 11, and controlled by a metering pin 12, the objects of the invention which primarily connected with an air valve 13.

contemplates a self feedingfcarburetor which An ordinary choke valvel l, is employed at i is not reliant upon gravity flow from the supthe inlet side of the carburetor and a throttle 65 ply tank, but which acquires its fuel from valve 15, shown at the opposite side of the a low level supply and retains, ready for-imair valve 13. A venturi restriction 16, is mediate vaporization, or for accelerating purshown between the air valve 13, and throttle poses, a sufficient supply at a level higher than 15, and located inthe "mixing chamber of the the main fuel tank. carburetor. 70

A further object is to accomplish these de-' 17 indicates t] e fuel induction tube which sirable results with the ordinary sizes of conextends into the accelerating well 9 and is duits, commonly employed as standards and adjustable up and downthat is in the diwithout incurring any serious variation in rection of its longitudinal axis. Besides hemixture, whether the supply tank is filled to ing hollow, this tube has its walls cut away, 75

its high level, or depleted toits low level. so as to furnish communication, near one end, Referring to the drawings: between its interior bore and the Well, as in- Figure 1, is a somewhatdiagrammatic view dicated at 18, Fig. 2, and near its other end illustrating the arrangement of the system. between its interior and the restricted por- I Figure 2 is a, vertical sectional view tion 16 of the venturi, as indicated at 24:. The 80 through the carbureting mechanism, particular shape of the openings or passages Figure 3, is a view in cross section on the 24: is not very material, as long as they are line 33 of Figure 2. v of a size to permit the desired movement of I Figuret, is a top plan view of the fuel fuel. In order to adjust the tube 17 in the induction tube. direction of its length, I prefer. to attach a. 5

Figure 5, is a detailed view of the metered freely rotatable screw threaded stem 20 to opening as it may be applied to the exterior the tend or .top plate 21 of the tube as repreof the tank illustrated in Figure 1. sented in Fig. 2 and cause this stem to engage Referring to the drawings, 1 indicates an with a threadcdportion of the body of the 40 internal combustion engine 2, a carburetor carbureter. The stem 20 is provided withan suitably connected thereto, and 3, a fuel tank exterior enlargement or a finger piece 22 by i which is'ordinarily located at'a level lower which it may be turned to permit adjustthan the carburetor. m-ents, as will be apparent.

Connecting the carburetor and fuel tank, The lower end of the fuel induction tube 17 45 there is a conduit 4, which has a dependent has a tapered slot 18, so that the higher the arm 5, reaching nearly to the bottom of the level of fuel in the accelerating well or chain fuel tank. berythe smaller the opening from exterior Preferablywithin the fuel tank, although to interior of the induction tube, above the it may be located exteriorly thereof, there is fuel level in the well. 50 a metered opening 6, in the connecting con- It will, of course, be at once apparent that oned as 10% rich with the metered opening 6, there is a broken column of fuel passing from the fuel tank to the chamber 9, during the operation of the engine due to air being taken into the conduit 4 by the induced suction eflects.

It is, therefore,'preferred to have the metered opening 6, within the tank, as it takes over a saturated air along with the fuel. This saturated air, of course, spreads out inthe chamber 9,'and is drawn through the tapered plot of the induction tube to the mixing cha1n If the machine to which this system is applied is unduly thrown out of level, as for instance, in running down hill, so that the fuel tank will be relatively higher than the carburetor and the en'gine is running, there will be a proper flow to the well 9. However, should the engine be stopped, the induced suction would cease and there would be no flow from the fuel tank through the carburetor, as therecould be no siphoning efi'ect.

The direct lift for the fuel is from the fuel level of the fuel tank to the metered opening 6, and from this point, there is not a solid column of fuel. No shut ofl valve is necessary at the carburetor and obviously, as the direct lift is all in the fuel tank, varying grades have no appreciable effect on the mixture proportions.

Of course, the varying level of fuel, in the main fuel tank, will affect the mixture ratio; but very slightly. For instance, with an eight inch tank, there would be but four inches for variation, if the-carburetor is-adjusted correctly with the tank halffilled and the. air valve 13, is weighted to give a constant suction of approximately 2 of mercury or 36" of gasolene. With such an adjustment, the variation of level of fuel in the main tank cannot cause a variation of over 10% and this percentage may be reckwith a full tank and 10% lean with an empty tank. This, of course, is negligible as affecting-the operation of the engine.

No constant level float is required with this system. There can be no flooding and adjustments may be made with great accuracy. The fuel induction tube 17, and the accel crating well or chamber 9, perform an important function in securing the desired carburation, as well as in drawing the fuel from the low level tank. Of course, the height of the level of fuel in the chamber 9, varies.

First, the saturated air, above the fuel level, is drawn through the induction tube through the portion of the uncovered slot 18, above the fuel level, the fuel level rises and partially closes the slot 18, to such a point that it adjusts itself to the prevailing depression in the mixing chamber. The level will then remain constant until there is a ariation in degree of the depression or suction.

It follows, that the degree of depression or suction in the mixing chamber will vary the degree of uncovered opening of the slot 18, and, level of fuel in the chamber 9. The greater the suction, the greater the exposed portion of the slot and the lower the fuel level.

The chamber 9, andslot 18, provide a temporarily rich mixture on a sudden opening of the throttle for accelerating or quick pickup.

Of course, a certain amount of air, rich 'with fuel, enters the chamber 9, and passes on to the mixing chamber thru the tube 17, and this will increase with the degree of suction of the engine, inasmuch as the com pensating air valve13, will. raise the metering pin 12, as suction increases beyond certain defined limits. In other Words, the speed of movement'of the broken column of fuel and air between the-main fuel tank and carburetor will vary with the engine speeds and the variable suctions and there will always be a proper compensation to maintain the feed and the residue in the Well 9, for quick acceleration of the engine.

Of course, if desired, the air valve 13, may be made adjustable by an adjustable tension spring, though it is preferred to use In-Figure 6, the metered opening z, is

formed in a T connection j, and'connects a duct Z, with a small chamber m. The latter is provided with a suitable cap 12., and a suitable strainer 0, may be arranged between the cap and the end of the chamber or the chamber itself may have an additional filling of dust collecting material.

v The duct Z, communicates with the fuel line p, and with a dependent tube 1', the latter extending nearly to the bottom of the fuel tank 3..

Of course, the T is secured in any convenient manner to a flange of the tank.

The advantages of arranging the metered air opening for the fuel line, outside the tank, reside in accessibility and renewing the strainer parts so that the air is always well filtered before entering. the small metered openin It precludes t tank and its contentswith dust, which would be drawn in through the filler cap, in the ordinary tank, where suction is employed for the provisions for e. possibility of fouling the 1,771,ese

an accelerating chamber connected with the mixing chamber, a valve at the entrance to the accelerating chamber, an air-valve controlling the same and varying its positions with variations of suction in the mixing chamher, a conduit connecting the accelerating chamber and supply tank and means for causing fuel and air to be'delivered by entrainment through the said conduit.

2. In a fuel feeding and carbureting system, a mixing chamber, a throttle at one end thereef, a venturi, an air valve automatically operable by the suction induced in the mixing chamber and venturi, an accelerating chamher having an inlet, a valve controlling said inlet and moved by the air valve, means in the line of fuel flow intermediate the accelerating chamber and mixing chamber for providing a variable fluid opening between said chambers dependent upon the height of liquid in the accelerating chamber and a conduit connecting the accelerating chamber and supply tank for delivering a liquid and a fluid there to.

3. In a fuel feeding and carbureting syntem, a mixing chamber having a venturi, throttle and air inlet valve, the latter'varying in its position according to the suction of the mixing chamber, an accelerating chamber connected withthe mixing chamber, an adjustable tube connecting said chambers, said tube having a tapered slot extending within the accelerating chamber, a fuel supply tank and a conduit between the supply tank and accelerating chamber, for delivering liquid anda fluid thereto. v

4:. In a fuel feeding and carbureting sysitem, a mixing chamber, a throttle at one end thereof, a venturi, an air valve automatically operable by the suction inducedin the mixing chamber and venturi, an accelerating chamher having a fuel inlet a valve controlling the said inlet and moved theair valve, means in the line of fuel flow etween the accelerating chamber and themixing chamber for providing a variable fluid opening between the said chambers dependent upon the height of liquid in the accelerating chamber, and a fuel conduit leading to the accelerating chamber.

J @SEPH G. COULOMBE. 

